1. Field of the Invention
The present invention relates to electrical connectors and more particularly to electrical connectors which are used for miniaturized, high density and high pin count applications.
2. Brief Description of Prior Developments
Recent advances in the design of portable or mobile electronic equipment have required that connector technology keep pace with the trends of miniaturization and functional complexity. Connectors used in such applications need to be more substantially densely packaged than was heretofore generally required. Such board to board types of connectors are usually used to interconnect two printed circuit boards in an "mezzanine" configuration. Such uses require connectors not only with smaller contact pitches, but, in some cases, with lower mating heights, as well. The resulting increased packaging density must ordinarily be achieved without significant sacrifice of mechanical ruggedness since such connectors may be subjected to unusually high stresses because of the nature of the application. For example, miniaturized or mobile type products are subject to high stresses if they are dropped or otherwise abused. Such high stresses have the potential for damaging connector housings, contacts and solder joints. Furthermore, the connectors themselves might separate if sufficient retention forces are not available.
The "blade-on-beam" connector design is commonly used for miniaturized designs of 0.8 mm and less. This design typically uses a single cantilever beam type of contact for the spring contact which mates an associated blade contact, which does not have spring characteristics. The contact beams generally can be of two configurations.
One such configuration is an edge stamped or "tuning fork" configuration in which the contact is blanked from flat material and reoriented 90 degrees when it is inserted into the housing so that the blanked edge of the beam is in contact with the blade. This design has the advantage that complex configurations which have a high degree of compliance can be easily stamped. The cantilever beam geometry can also be optimized by stamping an idealized shape into the profile of the beam. For example, a constant stress beam with a parabolic shaped thickness profile might be readily stamped. This approach might allow for lower contact height and tighter pitch contacts. The mounting of the contact in the housing is generally accomplished by individually stitching the contacts into the housings.
An alternative design makes use of a more conventional approach in which the beam is stamped so that the rolled edge of the material is in contact with the blade. In this case the contacts can usually be stamped on the same pitch as the final configuration, and the forms of the contact are created by bending the material during the die stamping operation. Although these beams are usually not quite as mechanically efficient as the edge stamped design, they often are more cost effective since they can be mass inserted or insert molded into the housing thus making assembly either easier or less costly from either a product or machine standpoint. This type of product is also easier to electroplate and the contact surface is usually superior to the edge stamped type of contact. second longitudinal section which is in contact with the exposed third longitudinal section of the first element.
Also encompassed within the invention of the present invention is a method for manufacturing the above described connector. A mold is first produced. This mold includes a first mold member having a planar section and a medial projection having a medial surface and opposed lateral surfaces.
The mold also includes a second mold member having a medial section and a pair of inner opposed lateral projections and a pair of outer opposed lateral projections the second member is capable of being superimposed over said first member such that each of said inner opposed lateral projections are positioned adjacent the opposed lateral surfaces of the medial projection of the first member and that each of said outer opposed lateral projections are adjacent the planar section of the first member such that a medial cavity and opposed lateral cavities are forward between said first and second members.
A pair of opposed conductive members having inner and outer terminal ends are then interposed between said first and second mold members such that the inner terminal ends are in spaced relation in the medial cavity. Each of the conductive members is interposed in contacting relation between one of the opposed lateral surfaces of the medial projection of the first member and one of the inner lateral projections of the first member. The conductive members pass through one of the lateral cavities and then are interposed in contacting relation between the planar section of the first member and one of the outer lateral projections. In manufacturing the receptacle element, the lateral cavities of the mold are at least partially filled with a liquid polymeric molding compound and allowing said molding compound to solidify so as to form opposed solid insulative lateral support structures each having one of said conductive elements embedded therein. In manufacturing the plug, the lateral cavities and the medial cavity are filled with the liquid polymeric molding compound.